Sleep-Loss Impact Tied to Race, Income

But a new study suggests that interrupted sleep can be an even bigger problem for African-American children and for those from lower socioeconomic levels.

Conducted by researchers from Auburn University and the University of Notre Dame, the study focuses on a sample of 166 African-American and Caucasian children ages 8 and 9 from a variety of socioeconomic levels.

The children each wore a small activity monitor for one week to measure their habits while they slept. They also kept diaries of their bedtimes and wake-up times, and gave reports of problems such as feeling sleepy during the day.

Cognitive tests measuring a range of different skills were used to determine how a child might be performing in school.

The results showed that when children slept well and had fairly consistent sleep schedules, the performance of African-American and poorer children was relatively similar to that of the white children on the tests.

But when their sleep was disrupted, black children from all income levels and children of both races from lower-income families did not perform as well on cognitive tests as did more affluent white children whose sleep was disrupted.

The findings held true even when specific sleep problems such as asthma were taken into account.

“The results build on a small but growing literature demonstrating that poorer sleep in children is associated with lower performance on school-related tests,” writes Joseph A. Buckhalt, a counseling and school psychology professor at Auburn and the study’s lead author.

Why African-American and disadvantaged children are more vulnerable to academic problems when they experience a lack of sleep is not yet known, he writes. Mr. Buckhalt recommends further research on the issue and on intervention strategies that might benefit minority and disadvantaged children.

The article, “Children’s Sleep and Cognitive Functioning: Race and Socioeconomic Status as Moderators of Effects,” appears in the January/ February issue of the journal Child Development.